Breast cancer survivors’ typhoid vaccine responses: Chemotherapy, obesity, and fitness make a difference

•Innate immunity plays a key role in immune responses to infections and vaccines.•A typhoid vaccine provided a window into the inflammatory immune response.•Chemotherapy was associated with poorer vaccine responses in cancer survivors.•Even relatively low fitness appeared to benefit inflammatory vaccine responses. To investigate breast cancer survivors’ inflammatory responses to typhoid vaccine as a window into their innate immune response to novel pathogens. This double-blind crossover trial randomized 158 breast cancer survivors to either the vaccine/saline placebo or the placebo/vaccine sequence. The relative contributions of age, cardiorespiratory fitness (VO2peak), type of cancer treatment, central obesity, and depression to interleukin (IL)-6, IL-1 receptor antagonist (IL-1Ra), and WBC vaccine responses were assessed pre-injection and 1.5, 3, 4.5, 6, and 7.5 h post-injection. The vaccine produced larger IL-6, IL-1Ra, and WBC responses than placebo, ps